1. Field of the Invention.
This invention relates generally to power trains and, more specifically, to flexible power trains in which the expansion and contraction of the power cable is used to control the amount of power applied to either the power train or a secondary source of power.
2. Description of the Prior Art.
The concept of unloading bulk materials with powered vehicles such as manure spreaders is well known in the art. Typically, the unloading units include some type of a power train to couple the power unit to the spreader and a pusher such as an endless chain or a cable actuated false end gate for forcing the bulk material to the one end of the box on the vehicle. For example, a typical manure spreader usually contains a pair of endless chains with slats therebetween which slide along the bottom of the spreader box. The slats pull the manure into a rotating beater which spreads the manure over the field. Still another embodiment of the manure spreader is shown in the Webb et al U.S. Pat. No. 2,263,748 which shows a sliding end gate pulled along the spreader box by a pair of cables. Similarly, another type of unloading device is shown in the Glass U.S. Pat. No. 3,211,308. The Glass patent also shows a system of cables for pushing material to the front of the forage box. These are typical of prior art unloading devices and boxes available and in use for unloading bulk material such as forage and manure.
One of the problems with virtually all of the box type spreaders is the buildup of material which occurs on the sidewalls of the spreader. The buildup occurs because it is extremely difficult to scrape the sidewalls of a spreader to get them clean. The buildup of material creates a problem in both the summer use and the winter use of the spreader. In the summertime, the buildup generally causes a decrease in the internal dimensions of the box which may result in sticking or binding of the pusher. In the winter time, the problem is more severe in that natural buildup is assisted by freezing which causes material to also freeze to the sides. When the weather warms up, some of the excess buildup will melt and run to the bottom of the spreader where it freezes again. This can freeze up the spreader rendering it virtually unuseable until the warm weather returns.
With all these prior art types of unloading devices, the spreader box is basically a wood or metal box for confining the bulk material. The present invention includes a unique power coupling for the spreader box which works particularly well with the unloading devices using a false end gate for pushing material out of the spreader. The power train comprises a sensing mechanism to determine if the torque on the train cable exceeds a predetermined level and a member to reduce the power applied to the power train or a secondary source of power if the torque exceeds a predetermined level.
Other features have been included in the spreader provide means for adjusting the horizontal position of the load to eliminate problems of spreading manure on slopes.
Another feature of the invention is that the spreader with the side wall attachments can better accommodate loose manure as well as manure containing large amounts of bedding.
Another feature of the invention is the use of a hydraulic system to power the unloading of the manure.
Another feature of the invention is the means for preventing the unit from freezing during cold weather.
One of the problems occurring with remotely powered units such as the aforedescribed spreaders is the variation in load that occurs under varying conditions. For example, in a manure spreader, a load of frozen material or heavy material will produce a large force on the beater. If the force becomes too large, it may break the beater. The present invention provides a means for sensing when the load becomes too heavy and for reducing the rate of feed of the bulk material into the beater.
One of the prior art solutions of eliminating problems of stress on equipment is to use a slip clutch which disengages the power shaft if the stress exceeds a predetermined value. Such a device is shown and described in the Yergens U.S. Pat. No. 2,626,000. However, such devices only disengage and do not provide a compensating or controlling force as does the present invention. Thus, the present invention is well suited for utilization with the type of spreader shown and described in FIGS. 1 - 9.